A. Field of the Invention
The field of the present invention relates generally to seating cushions used for the elimination and/or prevention of pain to the lower spine, coccyx and perineum region of the human body. More specifically, the present invention relates to such seat cushions that are configured as a U-shaped pad and which have a thermal emitting device, containing a temperature retaining material such as solid, gel or fluid-based compositions, to serve as an ice pack or heating pad to provide cooling or heat in addition to cushioning.
B. Background
As is commonly known, conventional seating for humans usually consists of a hard surface that supports the weight of the human body and a cushioning element to soften the seating surface. Cushioning of the seating surface is often achieved through the addition of a separate cushioning device or substance that attempts to alleviate the pressure on the points of the weight bearing portions of the human body, such as the ischial tuberosities as well as trochanters and the coccyx. A virtually infinite array of sizes and shapes of cushions are known to exist. Most are in the traditional “pillow” shape, being either round, square or rectangular in the major configuration and having rounded sides separated by the minor dimension of the cushion. Such cushions are primarily for decorative purposes and are not intended specifically to take into account the comfort or prevention of pain of the user. Prior art teaches that cushions constructed as seating devices are configured for the generic needs of the user and are often configured to correspond to the shape of the seating surface, such as a chair, stool or bench, and not to the anatomical needs of the user. Examples of this type of seat cushion is described in U.S. Pat. No. 4,563,785 to Samelson and U.S. Pat. No. 5,557,815 to Mintz et al.
When seating cushions are prescribed for medical conditions by clinicians or chosen by the user, often the determination of which cushion to use is based on the cushion's pressure distribution properties especially, under the ischial tuberosities and sacrum. Gel, fluid or air-based support provides a less-ridged base of support, examples of which are described in U.S. Pat. Nos. 4,660,238 to Jay and 5,378,045 to Siekman. The shape of the seating cushion also plays a significant role in determining its therapeutic or palliative properties, as exemplified by U.S. Pat. No. 6,523,202 to Loomos and U.S. Pat. No. 5,702,153 to Pliska. Concerning cushions to be used as therapeutic devices and/or devices to prevent injury or bodily stress, such cushions can be categorized by two primary types of functional needs. One type is those meant generally to be used by patients with conditions wherein sitting is either painful due to specific medical conditions, such as episiotomy sites or hemorrhoids. The other type is those meant to be used by the general public in situations that require lengthy periods of sitting, including workplace conditions, driving or by individuals confined to sitting in a wheelchair, wherein the seat cushion serves as a device to prevent injuries and discomfort to the lower spine, coccyx, and perineum region of the human body.
The physical act of sitting can be painful due to the pain associated with sheer stress combined with vertical pressure applied to the skeletal-muscular region of the spine as well as the elevated temperature and humidity in and surrounding the perineum. Thus, sitting for a long period on an unpadded surface can either exacerbate existing injuries or induce new injuries to these regions of the human body. Often, the common response for treating conditions that make sitting uncomfortable is to recommend the use of a circular-shaped or doughnut configured cushion. One problem associated with the circular doughnut shaped cushion, however, is that the cushion does not substantially eliminate pressure upon the ischia of a patient. In addition, because of the location of the aperture in the center of the doughnut cushion, the doughnut cushion is relatively difficult to use, requiring either a sense of balance and/or the ability to reposition oneself in the case of slippage. As a result, many patients who lack the physical strength or patience to reposition themselves if the cushion shifts, are often compelled or choose to forego using the doughnut shaped cushion in favor of a more stable type of cushion, often at the expense of the needed padding or cushioning. Because there is direct pressure on the ischia and surrounding anatomical region of the user when using the doughnut shaped cushion, patients who are prescribed this cushion are generally forced to manipulate the integral doughnut shape of the pillow in order to obtain relief by eliminating the direct contact and pressure on the coccyx. It is commonly known that some patients deflate the pillow in order to fold the doughnut in half, thereby creating a somewhat U-shaped cushion, to allow for full contact between the tuberosities as well as trochanters while alleviating direct pressure on the coccyx, making the traditional doughnut shape pillow take on a more effective shape to alleviate their symptoms.
Another shortcoming associated with the continuous pressure upon the ischia that can be caused by sitting on a circular doughnut-shaped cushion is that the resulting pressure can exacerbate pre-existing orthopedic discomfort. For example, a common condition that often necessitates a specially designed cushion or seating surface is coccygodynia, that is pain resulting from injury to the sacrococcygeal synchrondrosis. A common etiology of this condition is the result of hormonal changes associated with pregnancy that enable the synchondrosis between the sacrum and the coccyx to soften, and unlike fractures, which can remodel, injuries to this region can result in this synchondrosis being repeatedly forced out of its normal position, causing inflammation of the tissues surrounding the coccyx. Management of this condition includes having the patient sit on the usual air-filled doughnut-shaped cushion, however due to the shortcomings associated with the doughnut shape pillow discussed above, many of these patients are forced to either manipulate the shape of the pillow in order to create a comfortable sitting surface or forego the necessary padded seating surface.
Even more common for the general user is the pain and stress associated with driving long distance, as can be experienced by truck, bus or cab drivers. Commonly, individuals who must sit for extended periods while driving long distances often rely on a pillow or cushion not specifically configured for the alleviation of back or other discomfort while sitting in a vehicle. Typical cushioning apparatuses designed to alleviate stress or the discomfort associated with driving consist of seating devices configured as seating pads that are placed between the user and the seat for additional padding, as exemplified in U.S. Pat. No. 3,940,183 to Seltzer et al. However, as with the doughnut-shaped cushion, these devices often slip and become uncomfortable or hazardous for an individual while driving a vehicle. As with individuals who need to manipulate the shape of a cushion to obtain maximal comfort, driving necessitates a secure form of seating to avoid the seat manipulation that can be distracting and unsafe while driving. Even more specifically, the seat cushions that are configured for use for specific therapeutic conditions are generally designed to be used either at home, in an office or in a hospital setting, and are not designed for the wear and tear of everyday use as is experienced by individuals needing such a cushion for driving a vehicle. Seat cushions that are designed to ease back pain while driving, or seating cushions for the palliative support of the lumbar and related areas, are not usually configured to ensure that the sacrum and coccyx areas remain contact free for all users, particularly those with limited hip rotation, and provides no means for direct support of the lower back.
What is needed, therefore, is a cushion in a shape that provides sufficient padding to eliminate pressure upon the ischia of a user. Such a seat cushion should provide the increased advantage of providing heat or cooling to the perineum and ischial areas of the human body. The preferred cushion should be provided in a generally U-shaped configuration in order to conform to the anatomical areas of the human body that require support and padding. The preferred U-shaped cushion should have components which allow it to be secured to the seating surface, thereby providing a secure foundation wherein the cushion does not slip or shift with the movement of the user. The preferred U-shaped cushion should contain the option of directing heat or cold, as needed, to the portion of the human body near or in contact with the cushion. The preferred seat cushion should be constructed such that it is both durable and easily cleaned allowing it to be used in a wide variety of situations.